Improvement in door-locks



UNITED STATES NELSON WARREN, OF WILMINGTON, DELAWARE.

IM PROVEMENT IN DOOR-LOCKS.

Specification forming part of Letters Patent No. 121,142, dated November 21, 1871; antedated November 4, 1871.

To all lwhom it may concern:

Be it known that I, NELsoN WARREN, of Wilmington, in the coimty of New Castle and State of Delaware, have invented certain new and useful Improvements in Door-Locks; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawing making a part of this specieation.

My invention relates to that class of door-locks designed to frustrate any attempt at picking the same from the outside when locked on the inside; and consists in the construction of the tumbler so that it may be lifted at either end while the other virtually remains at rest.

To enable those skilled to make and use my improvement I will proceed to describe the same, referring by letters to the accompanying drawing, in which- Figure l is a top view of a lock embracing my invention, with the inside plate removed. Fig. 2 is the inside of said plate, it being shown as turned off, as by a hinge, to the right. Fig. 3 is a view of the bolt, and Fig. 4L a view of the under side of the tumbler.

Similar letters indicate like parts inthe several figures. v

A is what I denominate the outside plate, and B the inside one. Both are provided with the usual screw-holes, Sto. Key-holes G and E are provided on reverse sides of the lock, and so arranged as not to be opposite to each other, and have arranged opposite thereto, respectively, keyseats D F. Between the key-holes a partition,

a, is cast with plate A, thus effectually separating the two key-holes; and other divisions, T R, are cast with plate B for similar purpose. The tumbler Gis constructed, as shown clearly at Fig. 4, bifurcated to straddle the division-plate a, (although this will not, of course, be necessary where no such partition is used,) and having its ends constructed, as shown, to rest upon seats 1 and 2 provided on plate A, and having a post, I, about centrally located, cast or made therewith, against which the spring J bears, and which locks the bolt against movement except when the tumbler be lifted by the key. The bolt is made in the usual manner, with four cam-faces, for operation by the key at either key-hole, with a slot, O, to avoid the partition a, and two other slots, P Q, into which the post I drops.

It will be seen that, the parts all being retained in position between the plates A and B, andthe tumbler held against longitudinal movement by the stops or rests b and end plate H and supported on the stops 1 and 2, either end of the tumbler may be lifted while the other remains comparatively at rest.

A key-stop, M, is formed on the plate A,which is designed to arrest the key when the bolt is shot from the inside, so that its end will bear against the cam-face 3 of the bolt N and prevent retraction of the same, no matter how much the tumbler may be tampered with from the other key-hole. This, however, forms no part of my invention.

What I claim as new, and desire to secure by yLetters Patent, is- 

